Substituted dihydropyridine



3,074,951 SUBSTETUTED DlHYDROPYRlDlNE Herman Levin, San Antonio, Tern, assignor to B3 Service, Inc, Long Beach, Calif., a corporation of Delaware No Drawing. Filed Mar. 4, 1959, Ser. No. 797,031 2 Claims. (Ci. 260290) This invention relates to new pyridine derivatives having anti-corrosive properties and to the method for the preparation of the same.

More in particular this invention relates to the preparation of dihydropyridine.

This application is a continuation-in-part of my prior application Serial No. 425,326, filed April 23, 1954 now abandoned, entitled Corrosion inhibitor and Serial No. 603,794, filed August 13, 1956 entitled Hydropyridine Derivative now abandoned.

it is an object of the present invention to produce hydrogenated pyridine by imple condensation.

The present invention comprises the use of substances prepared by condensing in a liquid phase aliphatic and aromatic aldehydes with ammonia or an ammonia derivative in such a manner as to produce a substituted hydrogenated pyridine compound having a substituted group or groups containing 6 to 20 carbon atoms of the general formula 5 (3+a) b wherein a is an integer from through and b is an integer from 1 to 3, and the sum of a-l-b is greater than 2 and less than 7, and R represents at least one substance selected from the group consisting of alkyl and aryl; which substance is attached to the ring.

These condensations are carried out in the presence of ammonia (liquid or vapor) ammonium carbonate, ammonium sulfate or similar compounds which will release ammonia continuously to the reaction system during the course of the reaction.

Example 1 (Compound F) 21.3 g. (0.14 g.-mole) ammonium carbonate (31 wt. percent NH 81.7 g. (1.13 g.-mole) n-butyraldehyde heated to a temperature of 63 to 70 C. (145158 F.) under atmospheric pressure for 60 minutes. A light yellow oil phase (55.6 grams) was recovered. Vacuum distillation at 30 mm. Hg absolute and room temperature, using nitrogen gas, yielded 41 grams of a yellow liquid product which was experimentally found to have a molecular weight of 174. The major portion of the mixed product is 3,5 diethyl 2-propyl-dihydropyridine-(2,3) whose theoretical molecular weight is 179.

Example 2 (Compound E) 23 g. (0.15 g.-rnole) ammonium carbonate (31 wt. percent Ni-l 32.5 g. (0.28 g.-mole) n-heptaldehyde 40.9 g. (0.56 g.-mole) n-butyraldehyde heated to a temperature of 64 to 68 C. (147154 F.) under atmospheric pressure for 30 minutes. A yellow oil 3,074,95l Fatented Jan. 22, 1963 phase (63.3 grams) was recovered. Vacuum distillation at 30 mm. Hg absolute and room temperature, using nitrogen gas, yielded 37.2 grams of a yellow liquid product which was experimentally found to have a molecular weight of 210. The major portion of the mixed product is 5-amyl-3-ethyl-2-propyl-dihydropyridine-(2,3) whose theoretical molecular weight is 204.

Example 3 (Compound G) 15.8 g. (0.10 g.-mo1e) ammonium carbonate (31 wt. percent NH 51 g. (0.445 g.-mole) n-heptaldehyde 39.2 g. (0.89 g.-mole) acetaldehyde heated to a temperature of 25 to 60 C. (77140 F.) under atmospheric pressure for 24 minutes. A reddishyellow oil phase (62.5 grams) was recovered. Vacuum distillation yielded a similar colored liquid product. The major portion of the mixed product is S-amyl Z-methyldihydropyridine- (2,3

Example 4 (Compound I) Compound Chemical Name Com- Prepared by- Designation pound Hydrogenated E. 5-amyl-3-cthyl-2- E sodium ethanol.

propyl-tetrahydropyridine. Hydrogenated F. 3,5-diethyl-2-propyl- F Do.

tetrahydropyridine. Hydrogenated G. 5-amyl-2-methyl- G Do.

tetrahydropyridine. Hydrogenated H- 5-amyl-zpropyl-(1)- H Do.

tetrahydropyridiue. Hydrogenated I. 5-amyl-3-hexyl-(2,4)- I Do.

Z-amyl-tetra hydropyridine. Hydrogenated 1.. 5-amyl-2-ethyl-3- .T Do. methyl-tetrahydropyridine.

It has been found that these compounds reduce the corrosion of steel as much as 99.91% when exposed to extreme surface conditions at immersion in 15% by weight hydrochloric acid solution at a temperature of 300 F. and a pressure of 6,000 p.s.i., the concentration of the inhibitor being 0.15% by weight based on the concentration of the acid.

It will be evident from the above description that this invention provides new pyridine derivatives which will be of great interest because of their valuable properties to those desiring to protect metal from corrosion.

What is claimed is:

1. As a composition of matter, 5-amyl-2-propenyl-(l)- dihydropyridine- (2,3

2. As a composition of matter, 5-amyl-3-hexadienylidene- (2,3 -2-pentadienyl-( 1,3 -dihydropyridine-(2,3

References Cited in the file of this patent UNITED STATES PATENTS Haury July 25, 1950 Gluesenkamp et al Mar. 22, 1955 

1. AS A COMPOSITION OF MATTER, 5-AMYL-2-PROPENYL-(1)DIHYDROPYRIDINE-(2,3).
 2. AS A COMPOSITION OF MATTER, 5-AMYL-3-HEXYADIENYLIDENE-(2,3)-2-PENTADIENYL-(1,3)-DIHYDROPYRIDINE-(2,3). 